Legal Question in Credit and Debt Law in Ohio

In Ohio, your wife will be responsible for the debt as between her and the entity to whom money was owed on the property. The divorce decree can't change that. But if the ex did not make the payments as ordered by the divorce decree, then she will have a contempt of court action against him for his failure to pay. Upon bringing that action, the ex will likely be found in contempt and ordered to pay a sufficient amount of money to compensate your wife sufficiently to get rid of the judgment amount against her.

One other possibility would be to check the records of the case wherein she and her ex was sued to see if the Plaintiff in that matter ever got good service of process upon her. If not, you could file a motion to set aside the judgment for lack of jurisdiction if there was no good service of process.

Your course of action in this matter would depend greatly upon the amounts involved. If the amount in question is small, then I would say pay it and go after the ex for contempt. But if it is large, then it might make sense to hire an attorney to attempt to set aside the default judgment against your wife (and go after the ex for contempt).